160 Miscellaneous. 
Notice of some Freshwater and Terrestrial Rhizopods. 
By Pror. Lerpy. 
Prof. Leidy stated that among the ameeboid forms noticed by him 
in the vicinity of Philadelphia, there was one especially remarkable 
for the comparatively enormous quantity of quartzose sand which it 
swallowed with its food. The animal might be viewed as a bag 
of sand! It is a sluggish creature, and when at rest appears as 
an opaque white, spherical ball, ranging from 4 to 2 of a line in 
diameter. The animal moves slowly, first assuming an oval and 
then a clavate form. In the oval form one measured 2 of a line 
long by 2 of a line broad; and when it became clavate it was 2 of 
a line long by 3 of a line broad at the advanced thick end. Another, 
in the clavate form, measured 4 of a line long by 3 of a line wide 
at the thick end. The creature rolls or extends in advance, while 
it contracts behind. Unless under pressure, it puts forth no pseudo- 
pods; and the granular entosarc usually follows closely on the limits 
of the extending ectosarc. Generally the animal drags after it a 
quantity of adherent dirt attached to a papillated or villous discoid 
projection of the body. 
The contents of the animal, besides the granular matter and 
many globules of the entosarc, consist of diatoms, desmids, and 
confervee, together with a larger proportion of angular particles of 
transparent and mostly colourless quartz. Treated with strong 
mineral acids, so as to destroy all the soft parts, the animal leaves 
behind more than half its bulk of quartzose sand. 
The species may be named Am@sa saBuLosa, and is probably 
a member of the genus Pelomyxa of Dr. Greef (Archiv f. mikr. 
Anat. x. 1873, p. 51). 
The animal was first found on the muddy bottom of a pond in 
Dr. George Smith’s place in Upper Darby, Delaware County, but 
has been found also in ponds in New Jersey. 
When the animal was first noticed with its multitude of sand 
particles, it suggested the probability that it might pertain to a 
stage of life of Difflugia, and that by the fixation of the quartz 
particles in the exterior, the case of the latter would be formed. 
This is conjectural, and not confirmed by any observation. 
A minute ameeboid animal found on Spirogyra in a ditch at 
Cooper’s Point, opposite Philadelphia, is of interesting character. 
The body is hemispherical, yellowish, and consists of a granular 
entosarc with a number of scattered and well-defined globules, 
besides a large contractile vesicle. From the body there extends 
a broad zone, which is colourless, and so exceedingly delicate that 
it requires a power of 600 diameters to see it favourably. By this 
zone the animal glides over the surface. Delicate as it is, it evi- 
dently possesses a regular structure, though it was not resolved 
under the best powers of the microscope. The structure probably 
consists of globular granules of uniform size, alternating with one 
another, so that the disk at times appears crossed by delicate lines, 
and at others as if finely and regularly punctated. The body of 
